Premphase (conjugated estrogens and medroxyprogesterone acetate) is a hormone replacement therapy (HRT) prescribed for menopause symptoms. Premphase is the same drug as Prempro , taken at a different dosage level.

Approximately six million women are taking Prempro, a leading hormone replacement therapy (HRT) drug, to treat post-menopausal hot flashes and other menopause symptoms. However, a recent major study concludes that long-term use of Prempro is dangerous, significantly increasing the risk of stroke, blood clots, heart attacks, and breast cancer. It has been linked to the following side effects: dementia, Alzheimer's disease, stroke, blood clots, pulmonary embolisms, lupus, and breast cancer.

These results were found in the nation's biggest HRT study and were so alarming that the National Institutes of Health (NIH) prematurely canceled the study, citing risk to the study's participants. As a result, the study suggested that many of the women who use Prempro and other estrogen and progestin combinations should quit and talk to their doctors about alternatives.

The evidence is clear that Prempro and other estrogen-progestin combinations can actually harm perfectly healthy women. Women taking Prempro have a 29% higher risk of heart attack, 41% higher risk of stroke, and 26% higher risk of breast cancer.

Results of another study released on May 27, 2003 added to the health risks of HRT for post-menopausal women because it concluded the medications can double the risk of dementia and Alzheimer's disease.

Prempro is manufactured by Wyeth Pharmaceuticals, Inc. and it accounted for about $890 million of the company's $13.9 billion in sales in 2001.